poco/Zip/include/Poco/Zip/PartialStream.h
2008-10-31 09:18:26 +00:00

210 lines
7.1 KiB
C++

//
// PartialStream.h
//
// $Id: //poco/1.3/Zip/include/Poco/Zip/PartialStream.h#3 $
//
// Library: Zip
// Package: Zip
// Module: PartialStream
//
// Definition of the PartialStream class.
//
// Copyright (c) 2007, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
#ifndef Zip_PartialStream_INCLUDED
#define Zip_PartialStream_INCLUDED
#include "Poco/Zip/Zip.h"
#include "Poco/BufferedStreamBuf.h"
#include "Poco/Buffer.h"
#include <istream>
#include <ostream>
namespace Poco {
namespace Zip {
class Zip_API PartialStreamBuf: public Poco::BufferedStreamBuf
/// A PartialStreamBuf is a class that limits one view on an inputstream to a selected view range
{
public:
PartialStreamBuf(std::istream& in, std::ios::pos_type start, std::ios::pos_type end, const std::string& prefix, const std::string& postfix, bool initStream);
/// Creates the PartialStream.
/// If initStream is true the status of the stream will be cleared on the first access, and the stream will be repositioned
/// to position start
PartialStreamBuf(std::ostream& out, std::size_t start, std::size_t end, bool initStream);
/// Creates the PartialStream.
/// If initStream is true the status of the stream will be cleared on the first access.
/// start and end acts as offset values for the written content. A start value greater than zero,
/// means that the first bytes are not written but discarded instead,
/// an end value not equal to zero means that the last end bytes are not written!
/// Examples:
/// start = 3; end = 1
/// write("hello", 5) -> "l"
~PartialStreamBuf();
/// Destroys the PartialStream.
void close();
/// Flushes a writing streambuf
Poco::UInt64 bytesWritten() const;
protected:
int readFromDevice(char* buffer, std::streamsize length);
int writeToDevice(const char* buffer, std::streamsize length);
private:
enum
{
STREAM_BUFFER_SIZE = 1024
};
bool _initialized;
std::ios::pos_type _start;
Poco::UInt64 _numBytes;
Poco::UInt64 _bytesWritten;
std::istream* _pIstr;
std::ostream* _pOstr;
std::string _prefix;
std::string _postfix;
std::size_t _ignoreStart;
Poco::Buffer<char> _buffer;
Poco::UInt32 _bufferOffset;
};
inline Poco::UInt64 PartialStreamBuf::bytesWritten() const
{
return _bytesWritten;
}
class Zip_API PartialIOS: public virtual std::ios
/// The base class for PartialInputStream and PartialOutputStream.
///
/// This class is needed to ensure the correct initialization
/// order of the stream buffer and base classes.
{
public:
PartialIOS(std::istream& istr, std::ios::pos_type start, std::ios::pos_type end, const std::string& prefix, const std::string& postfix, bool initStream);
/// Creates the basic stream and connects it
/// to the given input stream.
/// If initStream is true the status of the stream will be cleared on the first access, and the stream will be repositioned
/// to position start
PartialIOS(std::ostream& ostr, std::size_t start, std::size_t end, bool initStream);
/// Creates the basic stream and connects it
/// to the given output stream.
/// If initStream is true the status of the stream will be cleared on the first access.
/// start and end acts as offset values for the written content. A start value greater than zero,
/// means that the first bytes are not written but discarded instead,
/// an end value not equal to zero means that the last end bytes are not written!
/// Examples:
/// start = 3; end = 1
/// write("hello", 5) -> "l"
~PartialIOS();
/// Destroys the stream.
PartialStreamBuf* rdbuf();
/// Returns a pointer to the underlying streambuf.
protected:
PartialStreamBuf _buf;
};
class Zip_API PartialInputStream: public PartialIOS, public std::istream
/// This stream copies all characters read through it
/// to one or multiple output streams.
{
public:
PartialInputStream(std::istream& istr, std::ios::pos_type start, std::ios::pos_type end, bool initStream = true, const std::string& prefix = std::string(), const std::string& postfix = std::string());
/// Creates the PartialInputStream and connects it
/// to the given input stream. Bytes read are guaranteed to be in the range [start, end-1]
/// If initStream is true the status of the stream will be cleared on the first access, and the stream will be repositioned
/// to position start
~PartialInputStream();
/// Destroys the PartialInputStream.
};
class Zip_API PartialOutputStream: public PartialIOS, public std::ostream
/// This stream copies all characters written to it
/// to one or multiple output streams.
{
public:
PartialOutputStream(std::ostream& ostr, std::size_t start, std::size_t end, bool initStream = true);
/// Creates the PartialOutputStream and connects it
/// to the given output stream. Bytes written are guaranteed to be in the range [start, realEnd - end].
/// If initStream is true the status of the stream will be cleared on the first access.
/// start and end acts as offset values for the written content. A start value greater than zero,
/// means that the first bytes are not written but discarded instead,
/// an end value not equal to zero means that the last end bytes are not written!
/// Examples:
/// start = 3; end = 1
/// write("hello", 5) -> "l"
///
/// start = 3; end = 0
/// write("hello", 5) -> "lo"
~PartialOutputStream();
/// Destroys the PartialOutputStream.
void close();
/// must be called for the stream to properly terminate it
Poco::UInt64 bytesWritten() const;
/// Returns the number of bytes actually forwarded to the inner ostream
};
inline void PartialOutputStream::close()
{
flush();
_buf.close();
}
inline Poco::UInt64 PartialOutputStream::bytesWritten() const
{
return _buf.bytesWritten();
}
} } // namespace Poco::Zip
#endif // Zip_PartialStream_INCLUDED